3D Stacked Dice Package With TSVs and Conductive Bumps
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Solution Overview
Problem
Current three-dimensional integrated circuit package structures face challenges in achieving reliable electrical connections and high-density packaging while minimizing electrical transmission delays and preventing conductive pad breakage.
Innovation Solution
The implementation of Through-Silicon-Vias (TSVs) technology with a redistribution layer and conductive bumps between stacked dice, along with a conductive pattern layer as a hard-mask, to establish vertical electrical connections and enhance the reliability of the package structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If Through-Silicon-Vias (TSVs) technology is employed to form vertical electrical connection structures, then electrical transmission speed is improved and electrical connection paths are shortened, but manufacturing complexity increases
Solution Approach 1:
The manufacturing process is divided into distinct stages: forming through-holes in substrates, stacking substrates with conductive pads, and filling vias with conductive material. This segmentation allows each step to be optimized independently while achieving the overall goal of creating vertical electrical connections for high-speed transmission.
Solution Approach 2:
The patent transitions from planar electrical connections to vertical three-dimensional connections through the implementation of TSVs. This dimensional change enables shorter electrical paths and higher transmission speeds while accommodating increased device density in the vertical direction.
2Reliability
If conductive pads are exposed between stacked dice for electrical connection, then electrical connectivity is achieved, but the conductive pads are susceptible to breakage and reliability decreases
Solution Approach 1:
Conductive bumps are formed on the conductive pads before stacking the dice. These bumps act as protective elements that prevent direct mechanical stress on the pads during subsequent processing and operation, thereby preventing breakage and enhancing reliability before failures can occur.
Solution Approach 2:
The electrical connection structure combines multiple materials: conductive pads (metallic), insulating layers (dielectric), and conductive bumps (solder or metal). This composite structure provides both electrical connectivity and mechanical protection, as the softer bump material absorbs stress while the rigid pad maintains electrical connection.
3Productivity
If multiple dice are stacked vertically to achieve high-density packaging, then device density and integration are improved, but manufacturing precision requirements increase
Solution Approach 1:
The conductive pads serve multiple functions: they provide electrical connection between dice, act as alignment features during stacking, and serve as bonding surfaces for conductive bumps. This multi-functionality simplifies the manufacturing process by eliminating the need for separate alignment structures, thereby reducing precision requirements while maintaining high device density.
Solution Approach 2:
Conductive bumps are formed on the pads before stacking occurs. This preliminary action creates self-aligning features that guide the positioning of stacked dice, reducing the precision requirements during the stacking process while ensuring accurate alignment for high-density packaging.
Data Source
AI summary
This invention provides a package structure of three-dimensional stacking dice and its manufacturing method. This invention employs the Through-Silicon-Vias (TSVs) technology to establish vertical electrical connection of the three-dimensional stacking dice and a redistribution layer between a blind hole-on-pad and a vertical through hole formed by the TSVs technology to direct the electrical connection from a first surface to an opposite second surface of this structure. In addition, this invention employs a conductive bump completely covering the pads jointed together between the stacking dice to avoid breakage of the pads. The reliability of the three-dimensional stacking dice of the present invention is increased.